Iraq has proved the skeptics right again. Just because there was no evidence of an Iraqi arsenal of weapons of mass destruction didn't mean that the weapons didn't exist. Conversely, the horrific revelations of the past week--evidence of an ongoing Iraqi program to build and maintain stocks of nuclear, chemical and biological weapons--do not mean that the program has ceased to exist.

According to the U.N. Special Commission on Iraq, headed by Ambassador Rolf Ekeus, Saddam Hussein's government was not only pursuing nuclear weapons; it had also produced thousands of gallons of germ warfare agents, including two of the most lethal, those causing botulism and anthrax, some of which had been kept in combat-ready warheads.

The new information came to light for the same reason our first hard evidence of Hussein's nuclear program emerged: because a defector had the goods on his government. The information has great credibility because the catalyst for its release was the defection of Hussein's own son-in-law, Lt. Gen. Hussein Kamel Majid, believed to be the architect of his father-in-law's program to acquire weapons of terror.

Confirmation of Iraq's secret biological weapons has appeared after four years of intensive effort to find them, which should temper the optimism of those who once asserted that everything Iraq had done to build weapons of mass destruction had been uncovered long ago. Two years ago, Maurizio Zifferero, an official of the International Atomic Energy Agency, declared the Iraqi case closed. The week before the new information came to light, he boasted that the agency's monitoring system was so sensitive that Iraq was finally unable to manufacture nuclear weapons without getting caught in the act.

Three years ago, Iraq was found to be deeply into the nuclear weapons business. Zifferero's team turned up parts for thousands of modern centrifuges to be used for enriching uranium and twin secret factories in which electromagnetic isotope separation technology was already being employed for the same purpose.

Now Ekeus reports that Iraq had accelerated its program to have a nuclear weapon by April, 1991, and that enrichment continued well after the war ended, a disconcerting surprise.